题解 | 构造C的歪

#include <stdio.h>

int main() {
	int a = 0;
	int b = 0;
	scanf("%d %d", &a, &b);
	int c = 0;
	if ((a + b) % 2 == 0) {
		c = (a + b) / 2;
	}
	else {
		c = b + (b - a);
	}
	printf("%d", c);
	return 0;
}